Add aliases for README file (#233)

Author: sajibcse68

docs/README.md

@@ -13,6 +13,7 @@ section_menu_id: getting-started
 url: /products/stash/0.5.1/getting-started/
 aliases:
   - /products/stash/0.5.1/
+  - /products/stash/0.5.1/README/
 ---
 
 [![Go Report Card](https://goreportcard.com/badge/github.com/appscode/stash)](https://goreportcard.com/report/github.com/appscode/stash)

docs/developer-guide/README.md

@@ -1,3 +1,4 @@
+---
 title: Overview | Developer Guide
 description: Developer Guide Overview
 menu:
@@ -10,6 +11,8 @@ product_name: stash
 left_menu: product_stash_0.5.1
 section_menu_id: developer-guide
 url: /products/stash/0.5.1/developer-guide/
+aliases:
+  - /products/stash/0.5.1/developer-guide/README/
 ---
 
 ## Development Guide